I know it is not only about capacity but facilities/access etc. But if we do go up and anyone chucks the capacity issue at us, it is worth bearing in mind the following current capacities:

Wrexflix (with al their circus) 13,341
Luton (in Prem last season) 12,056
Bournemouth (established Prem club) 11,307
County 10,852.
Wycombe (recently in Championship and with us in play offs) 10,446.
Leyton Orient (likely to be in play offs with us) 9.271.